bioturbation

[gremlin]

hmmm heard aobut this on the history channle. bioturbation. it seems to be good for life. and life makes it. wonder why the envrios have not heard of this problem.


In oceanography, limnology, pedology, geomorphology, and archaeology, bioturbation is the displacement and mixing of sediment particles (i.e. sediment reworking) and solutes (i.e. bio-irrigation) by benthic fauna (animals) or flora (plants). The mediators of bioturbation are typically annelid worms (e.g. polychaetes, oligochaetes), bivalves (e.g. mussels, clams), gastropods, holothurians, or any other infaunal or epifaunal organisms. Faunal activities, such as burrowing, ingestion and defecation of sediment grains, construction and maintenance of galleries, and infilling of abandoned dwellings, displace sediment grains and mix the sediment matrix. The sediment-water interface increases in area as a result of bioturbation, affecting chemical fluxes and thus exchange between the sediment and water column. Some organisms may further enhance chemical exchange by flushing their burrows with the overlying waters, a process termed bioirrigation. Benthic flora can affect sediments in a manner analogous to burrow construction and flushing by establishing root structures. Bioturbation is a diagenetic process and acts to alter the physical structure, as well as the chemical nature of the sediment.
http://en.wikipedia.org/wiki/Bioturbation

http://www.colby.edu/reload/chemistry/G ... ground.htm
Aiding in bioturbination, omnivorous crayfish are a benthic species will stir the benthos of shallow aspects of lakes. This action aids in the migration of G. echinulata colonies in situ. Also these organisms feed on plankton but not on G. echinulata due to its toxic nature. This reduces G. echinulata’s competing species further allowing it to flourish (Dorn and Wojdak 2004).